Implementing the Mechanistic–Empirical Design Guide Procedure for a Hot-Mix Asphalt–Rehabilitated Pavement in Indiana

Author(s):  
Khaled A. Galal ◽  
Ghassan R. Chehab

One of the Indiana Department of Transportation's (INDOT's) strategic goals is to improve its pavement design procedures. This goal can be accomplished by fully implementing the 2002 mechanistic–empirical (M-E) pavement design guide (M-E PDG) once it is approved by AASHTO. The release of the M-E PDG software has provided a unique opportunity for INDOT engineers to evaluate, calibrate, and validate the new M-E design process. A continuously reinforced concrete pavement on I-65 was rubblized and overlaid with a 13–in.-thick hot-mix asphalt overlay in 1994. The availability of the structural design, material properties, and climatic and traffic conditions, in addition to the availability of performance data, provided a unique opportunity for comparing the predicted performance of this section using the M-E procedure with the in situ performance; calibration efforts were conducted subsequently. The 1993 design of this pavement section was compared with the 2002 M-E design, and performance was predicted with the same design inputs. In addition, design levels and inputs were varied to achieve the following: ( a) assess the functionality of the M-E PDG software and the feasibility of applying M-E design concepts for structural pavement design of Indiana roadways, ( b) determine the sensitivity of the design parameters and the input levels most critical to the M-E PDG predicted distresses and their impact on the implementation strategy that would be recommended to INDOT, and ( c) evaluate the rubblization technique that was implemented on the I-65 pavement section.

Author(s):  
Tommy Nantung ◽  
Ghassan Chehab ◽  
Scott Newbolds ◽  
Khaled Galal ◽  
Shuo Li ◽  
...  

The release of the Mechanistic–Empirical Design Guide for New and Rehabilitated Pavement Structures (M-E design guide) generated a new paradigm for designing and analyzing pavement structures. It is expected to replace the commonly used empirical design methodologies. The M-E design guide uses a comprehensive suite of input parameters deemed necessary to design pavements with high reliability and to predict pavement performance and distresses realistically. However, the considerable amount of input needed and the selection of the corresponding reliability level for each might present state highway agencies with complexities and challenges in its implementation. An overview is presented of ongoing investigative studies, sensitivity analyses, and preimplementation initiatives conducted by the Indiana Department of Transportation (INDOT) in an effort to accelerate the adoption of the new pavement design guide by efficiently using existing design parameters and determining those parameters that influence the predicted performance the most. Once the sensitive inputs are identified, the large amount of other required design input parameters can be significantly reduced to a manageable level for implementation purposes. A matrix of trial runs conducted with the M-E design guide software suggests that a higher design level input does not necessarily guarantee a higher accuracy in predicting pavement performance. The software runs also confirmed the need to use input values obtained from local rather than national calibration. Such findings are important for state highway agencies such as INDOT in drafting initiatives for implementing the M-E design guide.


Author(s):  
Javed Bari ◽  
Matthew W. Witczak

Hydrated lime is often used as a mineral filler or antistripping additive in hot-mix asphalt (HMA). Many agencies across North America require the use of lime in all HMA mixtures being placed on high-volume roadways. Despite this wide use of lime, its effects on the HMA mixture dynamic modulus (E*) stiffness have rarely been evaluated. The new mechanistic–empirical (M-E) pavement design guide, Guide for Mechanistic–Empirical Design of New and Rehabilitated Pavement Structures, developed under NCHRP Project 1–37A uses E* as the primary material property of asphalt mixtures for the HMA characterization. A comprehensive study was completed at Arizona State University to assess the effect of lime addition on the E* stiffness of HMA mixtures. The study demonstrated that the standard test and design methodologies of the new M-E pavement design guide could be used effectively for lime-modified HMA mixes. With these methodologies, hydrated lime was found to increase the E* of HMA mixtures by 17% to 65% across the range of mixtures, lime contents, and temperature, with an overall average of 25% increase found from 17 mixture–lime percentage combinations across six different HMA mixes. This paper also outlines a provisional protocol for evaluating the E* master curve for lime-modified HMA mixtures using any of the three hierarchical levels found in the new NCHRP Project 1–37A pavement design guide.


2018 ◽  
Vol 217 ◽  
pp. 04001
Author(s):  
S. N. H. Umar ◽  
E. A. Bakar ◽  
N. M. Kamaruddin ◽  
N. Uchiyama

This study developed a new design of a low cost potentiostat circuit device. This device is an alternative electrochemical instrument applied for monitoring heavy metal ion in environmental water. It was developed to alleviate the cost burden of equipment procurement and due to the requirement for in-situ application since the existing commercialize devices are bulky and expensive. the main component of the device consist of electronics configuration of operational amplifier. the device was first modelled and simulated to acquire the design parameters and performance. the potential control algorithm was developed on open-source microcontroller platform. A dummy cell was used to validate the capabilities of the device.


2021 ◽  
Author(s):  
Chowdhury Jannatul Sifat E Ahmed

The AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) introduces a pavement design method which uses both the mechanistic analyses and empirical models to predict pavement distresses and performance, which needs to be calibrated to local conditions and engineering practices based on local pavement performance data. This thesis focuses on the local calibration of fatigue (both bottom-up and top-down) and thermal cracking models in MEPDG for superpave flexible pavements on Ontario’s highways. Simulations were run in the software, after developing a calibration database of Ontario’s provincial highway and the predicted data is compared to the observed data. Significant difference is found in the comparisons which need to be minimized by calibrating the distress models. A new regression model is used to optimize the calibration parameters by minimizing the standard deviations of the residuals between the predicted and observed distresses. The challenges encountered and concluding remarks developed during the local calibration process are discussed. Keywords: Local Calibration, Mechanistic Empirical Pavement Design Guide (MEPDG), Cracking Models, Fatigue Cracking, Thermal Cracking, superpave


2021 ◽  
Author(s):  
Chowdhury Jannatul Sifat E Ahmed

The AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) introduces a pavement design method which uses both the mechanistic analyses and empirical models to predict pavement distresses and performance, which needs to be calibrated to local conditions and engineering practices based on local pavement performance data. This thesis focuses on the local calibration of fatigue (both bottom-up and top-down) and thermal cracking models in MEPDG for superpave flexible pavements on Ontario’s highways. Simulations were run in the software, after developing a calibration database of Ontario’s provincial highway and the predicted data is compared to the observed data. Significant difference is found in the comparisons which need to be minimized by calibrating the distress models. A new regression model is used to optimize the calibration parameters by minimizing the standard deviations of the residuals between the predicted and observed distresses. The challenges encountered and concluding remarks developed during the local calibration process are discussed. Keywords: Local Calibration, Mechanistic Empirical Pavement Design Guide (MEPDG), Cracking Models, Fatigue Cracking, Thermal Cracking, superpave


2014 ◽  
Vol 668-669 ◽  
pp. 1434-1437 ◽  
Author(s):  
Hong Bo Zhang ◽  
Jing Hou ◽  
Yu Liu ◽  
Da Fa Xuan ◽  
Wei Min Fan

The main objective of this research is to explore the quantitative relationship between the pavement design parameters (structural layer thickness, voids, aggregate gradation and temperatures) and pavement performance parameters (rutting, cracking and IRI). The Mechanistic-Empirical Pavement Design Guide (MEPDG) was used and the analysis was performed on pavements under three temperature conditions namely the intermediate temperature zone (Zhengzhou in Henan Province), the low temperature zone (MOHE in Heilongjiang province) and the high temperature zone (Turpan in Xinjiang province). It was observed that 1) Pavement performances (rutting and cracking) were significantly impacted by layer thickness values until the values were larger than 14 inch; 2) Air void content influenced on not only predicted pavement rutting but also the thermal cracking.


2021 ◽  
Vol 109 (4) ◽  
pp. 243-260 ◽  
Author(s):  
Yves Wittwer ◽  
Robert Eichler ◽  
Dominik Herrmann ◽  
Andreas Türler

Abstract A new setup named Fast On-line Reaction Apparatus (FORA) is presented which allows for the efficient investigation and optimization of metal carbonyl complex (MCC) formation reactions under various reaction conditions. The setup contains a 252Cf-source producing short-lived Mo, Tc, Ru and Rh isotopes at a rate of a few atoms per second by its 3% spontaneous fission decay branch. Those atoms are transformed within FORA in-situ into volatile metal carbonyl complexes (MCCs) by using CO-containing carrier gases. Here, the design, operation and performance of FORA is discussed, revealing it as a suitable setup for performing single-atom chemistry studies. The influence of various gas-additives, such as CO2, CH4, H2, Ar, O2, H2O and ambient air, on the formation and transport of MCCs was investigated. O2, H2O and air were found to harm the formation and transport of MCCs in FORA, with H2O being the most severe. An exception is Tc, for which about 130 ppmv of H2O caused an increased production and transport of volatile compounds. The other gas-additives were not influencing the formation and transport efficiency of MCCs. Using an older setup called Miss Piggy based on a similar working principle as FORA, it was additionally investigated if gas-additives are mostly affecting the formation or only the transport stability of MCCs. It was found that mostly formation is impacted, as MCCs appear to be much less sensitive to reacting with gas-additives in comparison to the bare Mo, Tc, Ru and Rh atoms.


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